Add type definition to Vector Ecto type (#11)

Author: marcellofuschi

lib/pgvector/ecto/vector.ex

@@ -2,6 +2,8 @@ if Code.ensure_loaded?(Ecto) do
   defmodule Pgvector.Ecto.Vector do
     use Ecto.Type
 
+    @type t :: %Pgvector{data: binary()}
+
     def type, do: :vector
 
     def cast(value) do